Jave help MEGA PLEASE

Question

k so heres the first program
The game of Nim has two players alternately taking marbles from a pile. In each move the player must take at least one marble, but at most half of the marbles in the pile. The player who takes the last marble loses. Write a program in which the computer plays against a human opponent. Generate a random integer between 10 and 100 (inclusively) to denote the initial size of the pile of marbles. Generate a random integer between 0 and 1 to decide whether or the computer or the human takes the first turn. Generate a random integer between 0 and 1 to decide whether the computer plays smart or stupid. In stupid mode, the computer simply takes a random legal value between 1 and n/2 from the pile whenever it has a turn. In smart mode, the computer takes off enough marbles to make the size of the pile a power of 2 - 1 ---that is, 3, 7, 15, 31, or 63. That is always a legal move, except if the size of the pile is one less than a power of 2. In that case the computer makes a random legal move. Note that the computer can not be beaten in smart mode when it has the first move, unless the pile size happens to be 15, 31, or 63.
heres the class code
code:--------------------------------------------------------------------------------/*
* @(#)Nim.java 1.0 03/07/02
* Name: Alex Ionescu
* Period: 1
* Date: 9/18/03
* Assignment: Nim
* Purpose: Program Nim game in Java
package n;
import javax.swing.JOptionPane;
import java.util.Random;
import java.lang.Math;
import java.lang.String;
class Nim
     private int pile;
     private int turn;
     private int firstturn;
     private int stupid;
     private int smart;
     private int computer;
     private int user;
     private int first;
     public Nim()
          pile=(int)(Math.random()*90+10);
          smart=(int)(Math.random()*100);
          stupid=(int)(Math.random()*100);
          System.out.println("Pile size is "+pile);
          firstturn=(int)(Math.random()*100 + 1); //heres the 1/100 error
          computer=0;
          user=1;
          if(firstturn>50)
               firstturn=user;
          else
               firstturn=computer;
          firstturn=turn;
     public void play()
          if(smart>50)
               System.out.println("Computer is playing smart");
          else
               System.out.println("Computer is playing stupid");
          if(firstturn==user)
               System.out.println("You go first");
          else
               System.out.println("Computer goes first");
turn = firstturn;
          while(pile-1>0)
               if(turn==user)
                    String take = JOptionPane.showInputDialog("How many marbles do you want to take away?");
                    int take2= Integer.parseInt(take);
                    while(take2>(int)(pile/2))
                         JOptionPane.showMessageDialog(null, "Only take away half or less from the pile");
                         take = JOptionPane.showInputDialog("How many marbles do you want to take away?");
                         take2= Integer.parseInt(take);
                    pile= pile-take2;
                    System.out.println("There are "+pile+" marbles left");
                    turn=computer;
               else
                    if(smart>50)
                         pile -= smartTake();
                    else
                         pile -= stupidTake();
               turn=user;
     private int smartTake()
          int x = (int)(Math.random())*2-1;
          int sMarbles= (int)Math.pow(2,x);
          while (sMarbles > (.5 * pile) || sMarbles==0)
               x = (int)(Math.random())*2-1;
               sMarbles = (int)Math.pow(2,x);
               System.out.println("The computer took away " + sMarbles +" marbles");
               return sMarbles;
     private int stupidTake()
          int stMarbles = pile/2;
          while (stMarbles > (.5*pile) || pile==0)
                    stMarbles = pile/2;
          System.out.println("The Computer took away " + stMarbles +" marbles");
          return stMarbles;
the smartTake method is fucked because i just tried to make some shitty method to turn in so i had a grade
my errors are here...
in stupidTake method "In stupid mode, the computer simply takes a random legal value between 1 and n/2 from the pile whenever it has a turn."
im just plain stumped on this one
next error is in smart take.. it should take enough marbles away to make the size of the pile a power of 2 -1, which is 3, 7, 15, 31, or 63
i had something in mind like if pile>63 sMarbles = pile-63; pile=63;
but i did want to do it without making a bunch of if statements (think i might have to)
also in my constructor, i have firstturn Math.random() * 100 +1 but the user should only go first once in 100 turns, so this is fucked

Answer 1

k heeres the second program help
heres the driver
*@(#)Decode.java 1.0 03/12/10
*@author Alex Ionescu
*@since             Date 03/12/10
*@period 1
*@assignment Topic 6 Lab 1
*@purpose Replicate the postal service's method of translating bar codes and zip codes
package bar;
import javax.swing.JOptionPane;
class BarCodeDriver
     public static void main(String args[])
          String ask = JOptionPane.showInputDialog("Please enter a zipcode or barcode");
          Decode b = new Decode();
          Encode a = new Encode();
          char whatever = ask.charAt(0);
          if(whatever>=48 && whatever <=57)
               a.Encoding(ask);
          else
               if(whatever=='|')
                    b.Decoding(ask);
               else
                    JOptionPane.showMessageDialog(null, "You didn't enter a zipcode or barcode, please try again");
          System.out.println(" ");
          System.exit(0);          
}and the class
*@(#)Decode.java 1.0 03/12/10
*@author Alex Ionescu
*@since             Date 03/12/10
*@period 1
*@assignment Topic 6 Lab 1
*@purpose Replicate the postal service's method of translating bar codes and zip codes
package bar;
import javax.swing.JOptionPane;
class Decode
     private String Barcode;
     private int Digit;
     private int zipcode;
     private int count;
     private int startstring;
     private int endstring;
     private String digit;
     public Decode()
          count = 0;
          startstring = 1;
          endstring = 6;
          Digit = 0;
          zipcode= 0;
     //pre- expect 27 lines long barcode
     //post- return the barcode translated into a zipcode
     public void bartonum(String digit)
          if(digit.equals("||:::"))
               Digit=0;     
          else
               if(digit.equals(":::||"))
                    Digit=1;
                    else
                         if(digit.equals("::|:|"))
                              Digit=2;
                         else
                              if(digit.equals("::||:"))
                                   Digit=3;
                              else
                                   if(digit.equals(":|::|"))
                                        Digit=4;
                                   else
                                        if(digit.equals(":|:|:"))
                                             Digit=5;
                                        else
                                             if(digit.equals(":||::"))
                                                  Digit=6;
                                             else
                                                  if(digit.equals("|:::|"))
                                                       Digit=7;
                                                  else
                                                       if(digit.equals("|::|:"))
                                                            Digit=8;
                                                       else
                                                            if(digit.equals("|:|::"))
                                                                 Digit=9;
          System.out.print(Digit);
          zipcode= Digit + zipcode;
     //pre- expect a barcode with checkdigit,
     //post- return the bar code in zip code form     
     //convert barcode
     public void Decoding(String b)
          //Barcode = JOptionPane.showInputDialog("Please enter a bar code");               
          String digit = b.substring(startstring,endstring);
          for(count=0;count<=4;count++)
               bartonum((digit));
               startstring+=5;
               endstring+=5;
               digit = b.substring(startstring,endstring);
          //store sum of zipcode and checkdigit
          int woah = zipcode + Digit;
          //check to see if checkdigit is right
          if(woah % 10 == 0)
               System.out.println("...is the zipcode");
          else
               System.out.println("...that is not a correct bar code");
}it prints out this
11111Exception in thread "main" java.lang.StringIndexOutOfBoundsException: Strin
g index out of range: 31
at java.lang.String.substring(String.java:1477)
at bar.Decode.Decoding(Decode.java:123)
at bar.BarCodeDriver.main(BarCodeDriver.java:30)
its suppose to print out the 11111 but not the exception lol;